I just same across this earlier today, yes!
My use-case - which I’d welcome feedback on - is that I’ve built a home-brew system to gather fund prices and produce a daily email report of the top funds per (Morningstar) sector, the concept being that short-term investing in the funds which are consistently the best performing in well-performing sectors should be a good way to maximise returns.
I used to do this by spidering Trustnet, which was efficient and worked well - but then they moved to client-side JS rendering which would have meant migrating to use something such as Selenium to retrieve any data.
At this point I changed to using the ft.com Morningstar data - but many of these funds do not appear to be available from UK brokers. Given the lack of any available APIs to date I tried a highly rate-limited simple HEAD against HL’s public website… and got my IP banned for my efforts . YouInvest, on the other hand, has a much more sensible website that’s behind a CDN - but they’ve also raised questions with my ISP simply based on the volume of requests (although I’d argue surely not the impact - it’s at most a single HEAD per fund per day, and only for new SEDOL/ISINs which haven’t been previously encountered!). I had some success making the request via a public HTTP(s) proxy… but I should probably just migrate the whole setup to a cloud platform and get a Lambda/Function to populate the database.
@finki I don’t want to cause any harm to your service - what rate-limiting do you impose? I was planning simply to use the ‘ukSymbol’ call to confirm the existence of the given ISIN on freetrade/Trading 212 platforms… is this a reasonable plan? Is this the lightest-weight method of determining ISIN validity/availability?